more important than ratios are the pattern location, pattern overall look and individual swings structure.

B point is a way to destinguesh the patterns, is helpful, espcially when patterns are described for educational purposes and presented in the books, but from practical trading point of view B point is less important. There are valid tradable Gartley patterns with B on 78.6, or butterflies with B on 61.8.

Note this is just my opinion. Ortodox harmonic traders will say differently to public, but in the heart will agree with me